MassGeneral Hospital for Children (MGHfC) investigators found that a majority of interviewed smoking parents exposed their children to tobacco smoke in their cars, even though many had smoke-free policies at home. The study that will appear in the December 2012 issue of Pediatrics and has been released online, suggests that parents may not recognize the dangers of smoking in their cars with a child present.

"Workplaces, restaurants, homes and even bars are mostly smoke-free, but cars have been forgotten," says Emara Nabi-Burza, MBBS, MS, the study's lead author. "Smoking in cars is not safe for motorists and nonsmokers -- especially children, who have no way to avoid tobacco smoke exposure in their parent's car. Now that we know the magnitude of the problem, pediatricians and the public can act to help these children." Nabi-Burza is an investigator with the Center for Child and Adolescent Health Policy at MGHfC.

The authors write that tobacco smoke can contribute to an increased risk of respiratory infections, cancer and even death in children. Homes have traditionally been considered the main indoor source of smoke exposure for children, but recent studies have found elevated levels of tobacco smoke contaminants in cars, says Nabi-Burza, noting that children may spend a considerable amount of time in their family's car.

In the study, researchers interviewed 795 smoking parents about their car-smoking policy and behavior, including whether they exposed their children to tobacco smoke in their cars. The participants were interviewed while exiting from their child's doctors' office in one of 10 pediatric practices in eight states. Seventy-three percent of the parents admitted that someone had smoked in their car in the past 3 months. Of the 562 parents who did not have a smoke-free car policy, 48 percent smoked in the car when their children were present. Most parents adopted a "strictly enforced" smoke-free policy in their homes, but only 24 percent of parents had a strictly enforced smoke-free policy for their cars.

Only about one-fifth of the parents reported being asked by a pediatric health care provider about their smoking status. Few of the parents who smoked (12 percent) were advised by the provider to avoid smoking in their cars. This is the first known study to examine the rates at which pediatricians address smoking in cars; and due to the low percentage of parents counseled on this issue, the authors conclude that pediatricians should address tobacco use with parents and encourage them to have strict smoke-free home and car policies to help reduce tobacco smoke exposure of children.

Because of their role in advocating for children's health, Nabi-Burza says pediatricians have the unique opportunity to counsel parents on creating a strict smoke-free car policy.

"An infant strapped in a car seat cannot advocate effectively for herself in the face of parental tobacco addiction. The pediatrician can help the parent set a no-smoking policy in the car," says Jonathan P. Winickoff, MD, MPH, the study's senior author. He is an associate professor of Pediatrics and Nabi-Burza is a research associate in Pediatrics at Harvard Medical School.